Fig. 4.
Cerebral blood flow (CBF) and oxygen delivery (CDO2) at high altitude. Percent change in cerebral blood flow (Δ%CBF) during acclimation (>4 days above 3,400 m) in the eight studies at various altitudes reviewed in Ref. 5 (11, 79, 96, 119, 158, 166, 175, 201), and one recent investigation following 5 days at 4,350 m (158). As depicted, CDO2 is maintained at high-altitude due to the compensatory increase in CBF. As all studies were conducted during hypobaric hypoxia, PaCO2 was not controlled. TCCD, transcranial color-coded Doppler; gCBF, global cerebral blood flow. [Adapted from Ainslie and Subudhi (5) with permission. Copyright Mary Ann Liebert, Inc.]